Keep your hydraulic hoses safe and operational

25 September, 2015

The British Fluid Power Association (BFPA) considers some important aspects to consider when sourcing, fitting, maintaining or replacing hydraulic hose and hydraulic hose assemblies as part of a service and maintenance regime in mission-critical sectors such as quarries and mines.

Hydraulic hoses and hydraulic hose assemblies have an important part to play in the efficient running of many types of mobile plant. For example, in concert with the hydraulic power unit, pumps and motors, they are used for the supply of oil under pressure for motion control in high-powered machinery used in quarries and mines, such as excavators, blasthole drills and loaders. If they are supplied to the user or OEM to the correct specifications, and installed in accordance with current guidelines, they will likely operate reliably, safely and efficiently over long periods of time.

However, what sometimes gets forgotten is, because of the range of hydraulic hose available – such as thermoplastic/rubber, fabric/wire braided – wire spiral reinforcement etc. – it is important to bear in mind a number of points in order for equipment to suffer minimal downtime and be safe both for the operators and maintenance engineers.

Hydraulic hoses today should be clearly marked with information concerning the pressure rating and size etc. Different hoses on OEM equipment may have different pressure ratings. This is fine if the size and pressure for each hose is correct for the specific requirements asked of it; however never operate equipment without having confirmation that the specifications of the replacement hoses used are fit for the task at hand.

Guidance on suitability

One practice to avoid is the mixing of different suppliers’ fittings for use in the same hydraulic hose application. Not all providers supply the same sizes, thread forms or taper angles, even though two different fittings may look at face value to be roughly the same. Fittings have thread sizes that are often measured using a number of different formats, such as metric, BSP and NPT. Therefore if size and thread form information etc. is not written on the fitting, it is highly advisable to seek the guidance of specialist personnel who are capable of determining the correct thread form before a suitable fitting it is installed.

It is also important to tighten a hydraulic fitting to the torsion level specified by the manufacturer or supplier. Qualified fitters know that more torque doesn’t necessarily mean more oil tightness. Moreover, too much torque can end up damaging the fitting’s thread, making it difficult to unscrew and potentially reducing its efficiency and lifespan. Also, some hydraulic fittings tighten against a locking ring, clamping ring, taper or a soft seal, so if the fitting is over-tightened the rings or seals could become distorted or damaged – leading to premature failure.

The right mix

Additionally, it is inadvisable to mix fittings with different material specifications. By using fittings made of different materials on the same hose application corrosion may occur more easily, and this could result in failure further down the line even though the hose application might seem to work efficiently to being with.

Health & safety

Sourcing the right grade of hose and type of fitting is also important from a health & safety viewpoint. A high-pressure hydraulic oil injection injury may not happen very often, however when such an unfortunate situation does occur it is not only the injured individual whose health can be seriously affected; the question of professional responsibility, accountability and reputation of the contractor or site owner can also be raised.

Raising awareness

The British Fluid Power Association (BFPA) has established a number of programmes aimed at raising the awareness levels of people who work with hydraulic hose at all levels; from the system designer and field engineer, to the machine operator and the person who makes the hose. The BFPA runs the ‘Foundation Course in Working Safely with Hydraulic Hose and Connectors’, and a practical, workshop-based course titled ‘The BFPA Hose Assembly Skills Training Programme’, which takes the basic Foundation level of knowledge and trains attendees to a fully assessed level of ability in hose assembly techniques. Additionally, the BFPA has recently introduced a ‘Hose Integrity, Inspection and Management’ course. A number of reputable hose equipment and service providers are licensed to carry out these courses throughout the UK and Ireland.

High quality

And another important point – only trust your hydraulic hose and related equipment to a reputable hose equipment provider; whether the provider in question is a member of the BFPA Hose Accreditation Scheme or runs a reputable scheme of its own. When it comes to hose and fittings, do not accept anything but equipment of a high quality. After all, when the efficiency of your plant and equipment, as well as the health & safety of your workforce is at stake, only the best product, training and service provision is acceptable.

As a final point, never re-end or mix & match hose and fittings which have not been validated.